PHP: Generate random upper/lower case

gistfile1.php

<?php

$s = 'mynotsoverylongstring';

print randomcase($s);

function randomcase($string='') {
    $length = strlen($string);
    $chars = $string;
    $str = "";    
    
    for ($i = 0; $i < $length; $i++) {
        
        $r = rand(0, 1);
        if($r === 0) {
            $str.= strtoupper($chars[$i]);
        } else {
            $str.= strtolower($chars[$i]);
        }
    }
    return $rand_case_str;
}